Created attachment 62171 [details]
Presentation (one slide) that illustrates the problem.

Problem description: 
When a circle or other curved shape is combined with a picture (resulting in a picture with a transparent hole in it), the Slide show displays a larger polygon instead of the actual shape. 

Steps to reproduce:
1. In a new presentation, insert a picture from a file.  (Enlarge it if desired to fill the slide.)
2. From the Basic Shapes toolbar, select the Circle tool.  Draw a circle on the slide, on top of the inserted picture.
3. Select both the circle and the picture.  From the right-mouse menu, choose Combine.  The result is a transparent circular hole in the picture.
4. Start the slide show.  Instead of a circle, the transparent hole is a larger octagon.
(The same problem affects other shapes as well, including ellipse, ring, and cylinder.)

Current behavior:
Slide show displays the transparent hole as a larger polygon.

Expected behavior:
Slide show should display the shape correctly, as normal slide view does.

Platform (if different from the browser): 
MS Windows 7 Pro, v6.1.7601 SP1, on Dell Inspiron 620 (Core i5-2320).  Built-in Intel HD graphics.
              
Browser: Chrome/19.0.1084.46